Using logic, I can see two possible reason for being a block minimalist developer.
1) Since "Uh oh, here it is we who decide the size of the blocks", because having power is good. Since there is no consensus within the self appointed dominator group, we have to wait until the royals can come to agreement.
2) They want to suffocate bitcoin, permanently if possible, to get a head start on their endevour into competing systems.
Or the opposite of #1. As a developer, having power is very bad.
The goal of the project is to avoid centralization of power, and at least some are working on achieving that goal for themselves by divesting of it while it remains possible to do so. (BIP100)
This improvement proposal is the only significant one so far that removes the dev team from picking arbitrary numbers and dates and puts the size to the market of miners.
There are some other proposals on miners paying to a forward pool to increase the block size, but they are not so formalized yet.